Numerical Simulation of Nanorod Growth in REBa2Cu3Oy Superconducting Thin Films

Various nanostructures consisting of BaMO3(BMO) self-organize in REBa2Cu3Oy (REBCO) films prepared by vapor phase epitaxy. A numerical simulation of the BMO self-organization was developed using the three-dimensional Monte Carlo (3D-MC) method, and the effects of deposition parameters such as substrate temperature (Ts), deposition rate (vdep), and BMO volume fraction (fBMO) on BMO self-organization were investigated. We consider only the kinetic factors and ignore mismatch strain on the nanorods (NRs) morphology. 3D-MC simulations for various Tsindicated that the number density of BMO NRs decreased with an increase in Ts, and this tendency was similar to previous experimental results for BaHfO3-doped SmBCO films prepared by the pulsed laser deposition method. The effects of vdepand fBMOwere also simulated to provide contour plots of the number density of NRs with respect to Tsand fBMOat various vdep. Phase diagrams of nanostructures consisting of BMO with various vdepwere also obtained. Although these results do not take into account degradation of the superconducting properties and crystalline defects induced by nonoptimized conditions, they are considered to be a useful guideline for control of the flux pinning landscape on REBCO-coated conductors.